powerpc/powernv: Fix problems in onlining CPUs
At present, on the powernv platform, if you off-line a CPU that was
online, and then try to on-line it again, the kernel generates a
warning message "OPAL Error -1 starting CPU n". Furthermore, if the
CPU is a secondary thread that was used by KVM while it was off-line,
the CPU fails to come online.
The first problem is fixed by only calling OPAL to start the CPU the
first time it is on-lined, as indicated by the cpu_start field of its
PACA being zero. The second problem is fixed by restoring the
cpu_start field to 1 instead of 0 when using the CPU within KVM.
Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index cf9c69b..d4be7bb 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -65,7 +65,7 @@
lbz r0,PACAPROCSTART(r13)
cmpwi r0,0x80
bne 1f
- li r0,0
+ li r0,1
stb r0,PACAPROCSTART(r13)
b kvm_start_guest
1: